Dermacentor nitens; Essential oils; Mixture design; Nanoemulsion

Ticks from the Ixodes family are the main vectors of pathogens in animals and humans. Worldwide, the control of these arthropods causes losses of billions of dollars per year. The potential zoonotic vector Dermacentor nitens mainly affects equids. Essential oils individually and in combination, as well as nanoformulations synthesized by biopolymers, are a powerful ecological, economical, dose-reducing and less toxical alternative for non-target organisms. The essential oils of Clove (Syzygium aromaticum), Vetiver (Chrysopogon zizanioides), Basil (Ocimum basilicum), Lemongrass (Cymbopogon citratus), Laurel (Laurus nobilis) and Thyme (Thymus vulgaris), diluted to 10% in Tween 80, were tested individually and combined in Dermacentor nitens teleogynes. The best result was nanoemulsified with cashew tree gum. The Product Efficacy (EP) of Lemongrass, Vetiver and Basil showed better tick-killing activity. Then, these were combined into the pure, binary and tertiary proportions of the test optimization method, mixture planning. Binary and tertiary combination were unsatisfactory. Only the individual oils were considerable, with Vetiver (99.75%) being the only one with efficiency above 95%. The statistical data analyzed in Statistica 7.0 showed the absence of synergy and antagonism.